The Boston-based pizza chain Oath Pizza, which got its start on Nantucket in 2015, is opening its first NYC location on the Upper East Side on Wednesday, and today it will be rolling out a pizza truck and giving away half-pizzas to the first 100 customers. You can catch the truck from 12 p.m. to 2 p.m. on Liberty Street, and 3 p.m. to 5 p.m. on 57th Street and Lexington.

There will also be free pizza at their opening Wednesday on the Upper East Side, with half of every pizza on the house.

Oath’s signature crusts are grilled and seared in avocado oil, and for this New York location, they’re slinging unique menu items, like the Reuben pizza with pastrami sourced from Dickson Farmstand Meats, Russian dressing, and sauerkraut. So if you are longing for a Carnegie Deli Reuben, but you could also go for a slice, Oath’s might be worth a try.

If you need something to feel good about after consuming an entire Reuben pizza on a hot summer afternoon, know that Oath is the only Certified Humane pizzeria in the country. (The pies are made with ingredients that have no hormones, artificial preservatives or antibiotics.)

Oath, which has ten other locations in Boston and DC, will donate an “ongoing percentage of all sales of the Reuben” to Edible Schoolyard NYC, a non-profit that works with local public schools to persuade kids to eat healthy. On an unrelated note, Oath Pizza is also partnering with il Laboratorio del Gelato on a dessert special for its UES location: vanilla gelato “mixed with with Oath’s crunchy cinnamon sugar crust bites.”